Nil, energy, ice, or poison.
Habitat: Spiders tend to live near witches , though aren't uncommon in cave systems or the desert. Only energy-element spiders are capable of living in the desert, however.
Social Structure: Spiders are solitary monsters, and lack a social structure.
Reproduction: Reproduction happens sexually with spiders. Often, the male is eaten, and when he isn't, the female dies after laying her fist-sized eggs in the darkest corner she can find.
Appearance: Very large spiders with spindly legs and pronounced mouth-parts. They have very fat abdomens, sometimes covered in stripes, dots, or other markings. Their elements affect their coloration-- nil is black, dark violet is poison, and tan is energy. Energy spiders are much more thin than their mild-weather cousins.
Magic Use: Spiders can shoot a string of their element at threats and prey, slowing the prey and inflicting elemental damage.
Additional: Spiders are often one of the main foods for witches, but also one of the most basic servants for them.